A window washer was killed and his brother was seriously injured Friday when their scaffold fell nearly 50 stories from an apartment building on Manhattan's Upper East Side, authorities said.

The brothers were getting onto the scaffold from the roof of the 47-story building on East 66th Street when the platform gave way around 10:30 a.m., fire officials said.

"They apparently fell all the way from the top," said Fire Department spokesman John Mulligan.

Phil Stellar, who lives on the ninth floor of the building, was packing for a business trip when he said, "I heard a stunning rumble."

Edgar Moreno, 30, of Linden N.J., was pronounced dead at the scene; his 37-year-old brother was taken to New York Weill Cornell Medical Center in critical condition, officials said. His name was not released.

Officials said the company that employed them was City Wide Window Cleaning in Queens. A number listed for the company was out of service; a person who answered the telephone at a second number listed said she was only authorized to answer service calls and would not take a message seeking comment.

Parts of the scaffold and the body of the dead worker landed in a plaza outside the building. *lo** and flesh were spattered on a wall outside the building near residential windows. A doorman said the window washers had worked there for about three years.

Solow Management Corp.., the building's owner, issued a statement Friday extending sympathy to the workers' family and said it was cooperating with the investigation.

"It's a horrible, horrible tragedy and a reminder that life is very tentative," said Stellar.

About three hours after the accident, a piece of glass from a window on the top floor where the scaffold had been attached fell to the ground. Assembled media was immediately asked to clear the area.

No one was hurt when the glass fell, but the city Buildings Department ordered the street partially blocked until glass damaged by the falling scaffold was repaired; it also ordered repairs to a nearby home where debris fell through the skylights.

Scaffolds cover the facades of thousands of buildings in New York City, most on construction sites.

In 2006, 43 construction workers died on the job in New York, according to data from the federal Bureau of Labor Statistics. The death toll was up 87 percent from 2005, when 23 people died.